Concern about global warming eventually leads to discussions about the need to reduce the amount of carbon dioxide that pours into the earth's atmosphere on a daily basis from power plants and other industrial factories. At the same time, concerns about dwindling supplies of fossil fuels have encouraged the development of liquid fuels such as Ethanol as future replacement fossil fuels. The cost of preparation of feedstock, such as syngas generation is typically the most expensive part of GTF (Gas to Liquid) methods of producing a liquid fuel such as Ethanol. In the SMR process this cost typically represents about 50% of the total CAPEX (Capital Expense). Further the present SMR process is not particularly efficient and, unfortunately, results in as much or more carbon dioxide being introduced into the atmosphere as does burning fossil fuels.
The SMR process is a mature “catalytic” process that operates at about 870 degrees C. (1,600 degrees F.) and at pressures of between about 35 psig and 550 psig. As will be appreciated by those skilled in the art, the SMR process has been optimized for productivity and efficiency over many years of industrial applications. However, the process is limited to the use of gaseous and/or liquid feed-stocks only, and primarily operates on Methane gas as a Carbonaceous feedstock to produce Syngas (CO and H2). An F-T [Fischer-Tropsch] converter) is typically used with the SMR process to convert the resulting Syngas to Ethanol. Some existing SMR plants feedback the exhaust or tail gas from the F-T converter to the SMR reaction chamber to control, balance or selectively adjust the ratio of the H2 and CO in the resulting Syngas. Adjusting or balancing the H2/CO ratio of the Syngas is often desired or necessary because the Syngas leaving the SMR reactor typically contains an excess of H2 for efficient conversion by the F-T reactor. However, until this invention a separate stream of CO2 has never been used as an additional feed-stock.
The SMR reaction is:CH4+H2OCO+3H2, and the Water-Gas Shift reaction is:CO+H2OCO2+H2.
Therefore, a method for more efficiently producing a Syngas, (easily convertible to Ethanol and other liquid fuels) by the SMR process while at the same time removing CO2 from gaseous streams exhausted by industrial plants would offer many advantages in cost, as well as, an overall reduction in the carbon dioxide dumped into the atmosphere.